666777803 has 2 divisors, whose sum is σ = 666777804. Its totient is φ = 666777802.

The previous prime is 666777799. The next prime is 666777809. The reversal of 666777803 is 308777666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666777803 - 2² = 666777799 is a prime.

It is a super-3 number, since 3×666777803³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (666777809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333388901 + 333388902.

It is an arithmetic number, because the mean of its divisors is an integer number (333388902).

Almost surely, 2^666777803 is an apocalyptic number.

666777803 is a deficient number, since it is larger than the sum of its proper divisors (1).

666777803 is an equidigital number, since it uses as much as digits as its factorization.

666777803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1778112, while the sum is 50.

The square root of 666777803 is about 25822.0410308713. The cubic root of 666777803 is about 873.6290053039.

The spelling of 666777803 in words is "six hundred sixty-six million, seven hundred seventy-seven thousand, eight hundred three".